A block explorer is an application that allows for the examination of blockchains. These programs enable the user to view information as detailed as individual blocks, transactions and addresses at a given point in time. One can also view histories of forks and orphaned chains. Block explorers are specific to certain blockchains and can only examine the blockchain for which they are designed (i.e. Ethereum block explorers cannot review the Bitcoin blockchain). Notable block explorer applications include BlockExplorer, BlockCypher, and Etherscan.